This invention relates to a magnetic head for use in a data recording and reproducing device such as a video tape recorder or digital audio tape recorder, which devices use a rotary type head. More particularly, the invention relates to a rotary magnetic head which is wear-resistant and is used for high-density magnetic recording.
Magnetic tapes for data recording and reproducing devices, such as video tape recorders or digital audio tap recorders performing high-density magnetic recording operations, generally use iron oxide as the recording media; however, metal recording media has been extensively employed in order to increase the recording density.
In order to record data on such recording media with high accuracy, the magnetic head core material must have a high saturation magnetic flux density. Recently, to meet this requirement, a metal magnetic material high in saturation magnetic flux density, e.g., "Sendust" (trade mark), has been used instead of a ferrite.
However, the metal magnetic material described above has a lower wear-resistance than ferrite has. In order to overcome this problem, a magnetic head made of the metal magnetic material has been devised in various ways, for instance, as shown in FIGS. 9 and 10. More specifically, in a magnetic head having a magnetic core made of the metal magnetic material high in saturation magnetic flux density, as shown in FIG. 9, wear-resistant materials 1 are bonded to both sides of a head tip 7 in such a manner that they are perpendicular to an operating gap 2 in the tape slide surface of the head tip: or as shown in FIG. 10, wear-resistant films 8 are formed on both sides of the head tip 7 by vacuum deposition or sputtering, to increase the wear resistance of the magnetic core 6.
In the case of the head tip shown in FIG. 9, the magnetic core 6 is sandwiched between the wear-resistant materials 1, and the former is bonded to the latter, for example, with an adhesive. In this case, the wear-resistant materials 1 are arranged on both sides of the magnetic core 6 in such a manner as to define the tape slide surface of the head tip 7, thus increasing the wear resistance of the magnetic head.
In the case of the head tip shown in FIG. 10, the wear-resistant films 8 are formed on both sides of the magnetic core 6 by vacuum deposition or sputtering. In this case also, the wear-resistant films are arranged on both sides of the magnetic core 6 in such a manner as to define the tape slide surface of the head tip 7, thus increasing the wear resistance of the magnetic head.
In FIGS. 9 and 10, reference numeral 3 designates a winding window or core opening formed in the magnetic core; 4, winding grooves; and 5, glass used to set a track width and to join core blocks to form the magnetic core 6.
In the case of the magnetic head shown in FIG. 9, for the purpose of increasing the wear resistance, the step of sandwiching the magnetic core between the wear-resistant materials 1 is additionally included in the manufacturing procedure, with the result that the manufacturing cost is high. In the case of the magnetic head shown in FIG. 10, it is necessary to form the wear-resistant films on both sides of each of the head tips, thereby lowering the efficiency of production and increasing manufacturing costs. Furthermore, since the wear-resistant films are formed directly on the sides of the magnetic core, the adhesion of the films to the core is not sufficiently strong.
Also, in the case where the wear-resistant layer is formed by sputtering, the core block is exposed to plasma at a high temperature for a long period of time in order to form the relatively thick (i.e., 1 .mu.m) wear-resistant layer. As a result, a part of the wear-resistant layer may diffuse into the core block thereby producing a degenerative layer having deteriorated magnetic characteristics.